1. Field
This disclosure relates generally to switching circuits, and more specifically, to a switching circuit with a gate driver having a precharge period and method therefor.
2. Related Art
Switching circuits, such as high-side switches and low-side switches, are used for supplying power to motors, lights, and other devices. Various transistor types may be used to implement a switching circuit. A metal-oxide semiconductor (MOS) transistor is one such transistor type.
A high side switch and a low side switch may be coupled together in a commonly known half bridge configuration. Two half bridge configurations may be coupled together to form an H bridge configuration. Typically, in the half bridge configuration the on and off states of the high side and low side switches are timed to alternately drive a load. However, if both the high side switch and low side switch are on at the same time, a current path may exist between the power supply voltage terminals that may result in excessive power consumption. Therefore, when driving the high and low side switches, care must be taken to ensure both are not conducting at the same time. On the other hand, in many applications, it is desirable for the high side switch to be switched on as soon as possible after the low side switch is switched off. The use of relatively tight timing control may result in inadvertent overlapping “on” states in some process corners.
The speed of the circuit may also be increased by maximizing the ramp up rate of the output voltage of the high side switch during the transition from off to fully on. However, this may cause excessive electromagnetic inference (EMI) that is undesirable in some applications.
Therefore, what is needed is a switching circuit that solves the above problems.